The present invention relates to fiber-optic communications networks, and more particularly, to optical network equipment such as optical amplifiers that generate optical channel monitor and dynamic spectral filter alarms.
Fiber-optic networks are used to support voice and data communications. In optical networks that use wavelength division multiplexing, multiple wavelengths of light are used to support multiple communications channels on a single fiber.
Optical amplifiers are used in fiber-optic networks to amplify optical signals. For example, optical amplifiers may be used to amplify optical data signals that have been subject to attenuation over fiber-optic paths. A typical amplifier may include erbium-doped fiber coils that are pumped with diode lasers. Raman amplifiers have also been investigated. Discrete Raman amplifiers may use coils of dispersion-compensating fiber to provide Raman gain. Distributed Raman amplifiers provide gain in the transmission fiber spans that are used to carry optical data signals between network nodes.
In a typical network installation, a number of optical cards are installed in an equipment rack. The cards may include optical amplifier cards and cards for other network equipment. Optical amplifier modules may be provided on the optical amplifier cards. The optical amplifier modules may have input/output (I/O) pins that are connected to electronic components on the cards. Output pins may be used to indicate the detection of alarm conditions. Input pins may be used as control pins for control signals.
When an alarm condition is detected, an optical amplifier module may activate an appropriate alarm pin. Alarms may include loss of signal alarms, loss of output power alarms, reflected power alarms, case temperature out of range alarms, etc. A single pin can be used to signal the presence of an alarm condition. Data that identifies the type of alarm that is present may then be provided using a data port.
Control pins may be used to receive disable commands that turn all pumps off while allowing electronic components to remain on, reset commands that initiate soft boot procedures for the amplifier module, and eye safe commands that turn the powers of pumps in the optical amplifier module to an eye safe level.
Alarms are generally not available for conditions relating to the spectrum of the optical signals being handled by the equipment module or the status of module components such as dynamic filters.
It is an object of the present invention to provide optical network equipment modules such as optical amplifiers that generate optical channel monitor and dynamic spectral filter alarms.
This and other objects of the invention are accomplished in accordance with the present invention by providing optical amplifier modules and other optical network equipment modules for use in fiber-optic communications links in fiber-optic networks. The modules may be installed in optical network equipment cards such as optical amplifier cards or other optical network equipment subsystems. The cards may be mounted in network equipment racks and may be used to support network operations at network nodes in the fiber-optic communications links.
The optical network equipment modules may include optical channel monitors. The optical channel monitors may be used to make spectral measurements. The results of the spectral measurements may be used to generate alarms. Alarms that may be generated include loss of input signal alarms, loss of output signal alarms, loss of input band alarms, loss of output band alarms, active channel out of range alarms, alarms indicating that certain channels are inactive, gain out of range alarms, gain ripple out of range alarms, output power ripple out of range alarms, ripple out of range warning alarms, etc.
The optical network equipment modules may also include dynamic spectral filters. The dynamic spectral filters may be used in optical amplifiers to modify optical gain and power spectra. The status of the dynamic filters may be monitored in real time using control units in the equipment modules. Information on the status of the dynamic filters may be used to generate alarms. For example, alarms may be generated such as dynamic filter out of range warning alarms, dynamic filter out of range alarms, dynamic filter temperature out of range alarms, etc.
Users may be provided with an opportunity to modify alarms or alarm parameters to create custom alarms related to the operation of the optical channel monitor and dynamic filter.
Further features of the invention and its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.